Single crystal semiconductor nanowires are expected to be applied to various industries such as chemical sensors, biosensors, environmental sensors, field-effect transistors, and energy harvesting because of their unique and superior electronic, optical, mechanical, thermal and chemical properties.
The nanowire manufacturing method can be roughly divided into a bottom-up process and a top-down process. The bottom-up process has difficulties in controlling the position and shape of the nanowires and has low reproducibility. The top-down process has the advantage of being able to control the position and shape and has high reproducibility, but lithography equipment and processes such as Immersion ArF Scanners, Extreme Ultra-violet (EUV) laser beams, and electron beams for manufacturing nanowires are too expensive, thereby hindering the industrial application of nanowires. In addition, in a horizontal nanowire, two axes, except for one long axis, must have a nano-size (usually not larger than 100 nm). To accomplish this, the nanowire must be electrically isolated from the substrate. However, there is no reproducible method for manufacturing single crystal nanowires electrically isolated from the substrate, except for the expensive method of using a silicon-on-insulator (SOI) substrate, so it is essential to develop a new manufacturing method.